[pve-devel] [PATCH v2 qemu 3/3] add patch for loading a snapshot with qemu-img dd

[Fabian Ebner <f.ebner@proxmox.com>]

Will be used when cloning from a qcow2 efidisk.

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
---

New in v2.

 ...-add-l-option-for-loading-a-snapshot.patch | 129 ++++++++++++++++++
 debian/patches/series                         |   1 +
 2 files changed, 130 insertions(+)
 create mode 100644 debian/patches/pve/0049-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch

diff --git a/debian/patches/pve/0049-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch b/debian/patches/pve/0049-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch
new file mode 100644
index 0000000..f239cd4
--- /dev/null
+++ b/debian/patches/pve/0049-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch
@@ -0,0 +1,129 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fabian Ebner <f.ebner@proxmox.com>
+Date: Mon, 7 Feb 2022 14:21:01 +0100
+Subject: [PATCH] qemu-img: dd: add -l option for loading a snapshot
+
+Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
+---
+ docs/tools/qemu-img.rst |  6 +++---
+ qemu-img-cmds.hx        |  4 ++--
+ qemu-img.c              | 33 +++++++++++++++++++++++++++++++--
+ 3 files changed, 36 insertions(+), 7 deletions(-)
+
+diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst
+index a49badb158..1039aec01c 100644
+--- a/docs/tools/qemu-img.rst
++++ b/docs/tools/qemu-img.rst
+@@ -492,10 +492,10 @@ Command description:
+   it doesn't need to be specified separately in this case.
+ 
+ 
+-.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT
++.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [-l SNAPSHOT_PARAM] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] if=INPUT of=OUTPUT
+ 
+-  dd copies from *INPUT* file to *OUTPUT* file converting it from
+-  *FMT* format to *OUTPUT_FMT* format.
++  dd copies from *INPUT* file or snapshot *SNAPSHOT_PARAM* to *OUTPUT* file
++  converting it from *FMT* format to *OUTPUT_FMT* format.
+ 
+   The data is by default read and written using blocks of 512 bytes but can be
+   modified by specifying *BLOCK_SIZE*. If count=\ *BLOCKS* is specified
+diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
+index f3b2b1b4de..e77ed9347f 100644
+--- a/qemu-img-cmds.hx
++++ b/qemu-img-cmds.hx
+@@ -58,9 +58,9 @@ SRST
+ ERST
+ 
+ DEF("dd", img_dd,
+-    "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [-n] [bs=block_size] [count=blocks] [skip=blocks] [osize=output_size] if=input of=output")
++    "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [-n] [-l snapshot_param] [bs=block_size] [count=blocks] [skip=blocks] [osize=output_size] if=input of=output")
+ SRST
+-.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] if=INPUT of=OUTPUT
++.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [-n] [-l SNAPSHOT_PARAM] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] if=INPUT of=OUTPUT
+ ERST
+ 
+ DEF("info", img_info,
+diff --git a/qemu-img.c b/qemu-img.c
+index 015d6d2ce4..7031195e32 100644
+--- a/qemu-img.c
++++ b/qemu-img.c
+@@ -4922,6 +4922,7 @@ static int img_dd(int argc, char **argv)
+     BlockDriver *drv = NULL, *proto_drv = NULL;
+     BlockBackend *blk1 = NULL, *blk2 = NULL;
+     QemuOpts *opts = NULL;
++    QemuOpts *sn_opts = NULL;
+     QemuOptsList *create_opts = NULL;
+     Error *local_err = NULL;
+     bool image_opts = false;
+@@ -4931,6 +4932,7 @@ static int img_dd(int argc, char **argv)
+     int64_t size = 0, readsize = 0;
+     int64_t block_count = 0, out_pos, in_pos;
+     bool force_share = false, skip_create = false;
++    const char *snapshot_name = NULL;
+     struct DdInfo dd = {
+         .flags = 0,
+         .count = 0,
+@@ -4968,7 +4970,7 @@ static int img_dd(int argc, char **argv)
+         { 0, 0, 0, 0 }
+     };
+ 
+-    while ((c = getopt_long(argc, argv, ":hf:O:Un", long_options, NULL))) {
++    while ((c = getopt_long(argc, argv, ":hf:O:l:Un", long_options, NULL))) {
+         if (c == EOF) {
+             break;
+         }
+@@ -4991,6 +4993,19 @@ static int img_dd(int argc, char **argv)
+         case 'n':
+             skip_create = true;
+             break;
++        case 'l':
++            if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
++                sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,
++                                                  optarg, false);
++                if (!sn_opts) {
++                    error_report("Failed in parsing snapshot param '%s'",
++                                 optarg);
++                    goto out;
++                }
++            } else {
++                snapshot_name = optarg;
++            }
++            break;
+         case 'U':
+             force_share = true;
+             break;
+@@ -5050,11 +5065,24 @@ static int img_dd(int argc, char **argv)
+     if (dd.flags & C_IF) {
+         blk1 = img_open(image_opts, in.filename, fmt, 0, false, false,
+                         force_share);
+-
+         if (!blk1) {
+             ret = -1;
+             goto out;
+         }
++        if (sn_opts) {
++            bdrv_snapshot_load_tmp(blk_bs(blk1),
++                                   qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),
++                                   qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),
++                                   &local_err);
++        } else if (snapshot_name != NULL) {
++            bdrv_snapshot_load_tmp_by_id_or_name(blk_bs(blk1), snapshot_name,
++                                                 &local_err);
++        }
++        if (local_err) {
++            error_reportf_err(local_err, "Failed to load snapshot: ");
++            ret = -1;
++            goto out;
++        }
+     }
+ 
+     if (dd.flags & C_OSIZE) {
+@@ -5203,6 +5231,7 @@ static int img_dd(int argc, char **argv)
+ out:
+     g_free(arg);
+     qemu_opts_del(opts);
++    qemu_opts_del(sn_opts);
+     qemu_opts_free(create_opts);
+     blk_unref(blk1);
+     blk_unref(blk2);
diff --git a/debian/patches/series b/debian/patches/series
index daaff7c..a02a2d7 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -61,3 +61,4 @@ pve/0045-block-io-accept-NULL-qiov-in-bdrv_pad_request.patch
 pve/0046-block-add-alloc-track-driver.patch
 pve/0047-PVE-whitelist-invalid-QAPI-names-for-backwards-compa.patch
 pve/0048-PVE-savevm-async-register-yank-before-migration_inco.patch
+pve/0049-qemu-img-dd-add-l-option-for-loading-a-snapshot.patch
-- 
2.30.2